The cumulative helium mass spectrometric combination leak test method, which uses helium as both gross-leak test tracer gas and fine-leak test tracer gas, is a hermeticity test method, but it is defective for its high detection missing rate and is questioned in credibility. Thus, an improved combination test method is proposed by using the argon as gross-leak test tracer gas.
This improved cumulative helium mass spectrometric combination test method, which is related the US Patent Application Publication No. US2015/0073726 A1, included using argon as gross-leak test tracer gas and using helium as fine-leak test tracer gas, in addition to a number of other improvements. The Patent Application effectively extended the range of applicable rigor grade τHemin and a cavity volume V for the components under detection, and improved the credibility of detection.
The improved combination test method is still not ideal in the detectable range of the cavity volume V when the components under detection have lower rigor grade τHemin. And there is still a certain detection missing rate of fine/gross-leak test, the credibility needs further improved.